William Kingdon Clifford

“We may believe what goes beyond our experience, only when it is inferred from that experience by the assumption that what we do not know is like what we know.”

“In like manner, if I let myself believe anything on insufficient evidence, there may be no great harm done by the mere belief; it may be true after all, or I may never have occasion to exhibit it in outward acts. But I cannot help doing this great wrong towards Man, that I make myself credulous. The danger to society is not merely that it should believe wrong things, though that is great enough; but that it should become credulous, and lose the habit of testing things and inquiring into them; for then it must sink back into savagery.”

“It is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence.”